Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).
Also seek emergency medical attention if you have symptoms of a serious heart problem: fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness (like you might pass out).
Call your doctor at once if you have:
- a seizure;
- ringing in your ears, trouble hearing;
- severe muscle weakness, loss of coordination, underactive reflexes;
- low blood cell counts–fever, chills, tiredness, mouth sores, skin sores, easy bruising, unusual bleeding, pale skin, cold hands and feet, feeling light-headed or short of breath;
- low blood sugar—headache, hunger, sweating, irritability, dizziness, fast heart rate, and feeling anxious or shaky; or
- a serious drug reaction that can affect many parts of your body–skin rash, fever, swollen glands, muscle aches, severe weakness, unusual bruising, or yellowing of your skin or eyes.
Taking chloroquine long-term or at high doses may cause irreversible damage to the retina of your eye. Stop taking chloroquine and tell your doctor if you have:
- blurred vision, trouble focusing, trouble reading;
- distorted vision, poor night vision;
- changes in your color vision;
- hazy or cloudy vision;
- seeing light flashes or streaks, seeing halos around lights; or
- increased sensitivity to light.
Common side effects may include:
- nausea, vomiting, diarrhea, stomach cramps;
- unusual changes in mood or behavior;
- hair loss; or
- changes in hair or skin color.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.Chloroquine side effects (more detail)
Chloroquine overdose is advocated as a means of suicide in a French book Suicide Mode d’Emploi. The toxicity of this drug in overdose is often underestimated by doctors and patients. We describe three cases of deliberate self-harm with chloroquine and discuss its toxic effects and recent advances in management of these cases. Source PDF
There are concerns about the high doses used in some trials, as the drugs can have lethal side effects. Indeed, chloroquine has been used extensively in suicide attempts, particularly in France.